Work machines such as, for example, on-highway and off-road haulage vehicles, wheeled tractors, track type tractors, and various construction work machines, may receive motive power from one or more of different types of engines. For example, a work machine may be powered by one or more gasoline engines, one or more diesel engines, or one or more gas turbine engines. Work machines powered by one or more gas turbine engines may use the one or more gas turbine engines to drive a mechanism or mechanisms that may be used to transfer engine power output into work machine propulsion or other work machine operations.
A gas turbine engine may include a compressor section, a combustor section, and a turbine section. Air may be inducted into the compressor section to be suitably compressed. Subsequently, the compressed air may be delivered from the compressor section to the combustor section. Compressed air and fuel may be ignited in the combustor section to create hot exhaust gases. Hot exhaust gases exiting the combustor section may be delivered to the turbine section to be driven by the expansion of the hot gases. The mechanical power from the turbine section may then be used to drive the compressor section by way of a suitable shaft or other drive arrangement. At the same time, the power from the turbine section may be used to drive a suitable mechanism such as, for example, a generator.
A gas turbine engine may also include a recuperator section. A recuperator section may be used to recover, or recuperate, heat from hot exhaust gases that might otherwise be lost to the atmosphere. The recuperator section may include flow paths for hot exhaust gases passing from the turbine section, and flow paths for compressed air passing from the compressor section to the combustor section. In this way, there may be an exchange of heat between the hot exhaust gases and the relatively cooler compressed air whereby the compressed air is elevated in temperature before entering the combustor section and the hot exhaust gases are lowered in temperature before entering the atmosphere.
Where multiple gas turbine engines are used in a system, each of a plurality of gas turbine engines may be provided with its own recuperator section providing flow paths for the compressed air and hot exhaust gases of only that particular gas turbine engine. Fluctuations in power demands requiring one or more of a plurality of gas turbine engines to be shut down periodically would ordinarily dictate that the associated recuperator section or sections for the one or more gas turbine engines would be unused during shut down. For fluctuating power demands requiring one or more of a plurality of gas turbine engines to be shut down periodically, it would be useful to provide a system, structure, and method whereby multiple gas turbine engines could operate economically and efficiently with a single, common recuperator section.
One system involving multiple turbines and recuperators is described in U.S. Pat. No. 5,799,484 (the '484 patent) issued to Nims on Sep. 1, 1998. The '484 patent describes a system using a single combustor, single fuel supply system, and single electronic unit for two turbogenerators. The '484 patent provides a compressor and a turbine for each of the two turbogenerators. In addition, first and second recuperators for the two turbogenerators are arranged such that the entire recuperator volume of the two recuperators may be used for both single and dual turbogenerator operating modes.
Although the system described in the '484 patent may disclose using the entire recuperator volume of two recuperators for the flow of exhaust gases, both when operating one or both of the disclosed turbogenerators, the '484 patent maintains independent flow paths for the compressed air delivered by the two compressors of the two turbogenerators which is to be heated within the recuperator.
When the system of the '484 patent operates in a single turbogenerator mode, the flow path for compressed air in the recuperator for the idle turbogenerator is connected by way of a valve to serve the operating turbogenerator. However, the flow path for compressed air is not shared during the dual turbogenerator mode. Moreover, the '484 patent does not recognize grouping multiple gas turbine engines adjacent a common, shared recuperator. Rather, the '484 patent contemplates a single gas turbine engine, with one combustor, having plural compressors and turbines with separate recuperators, without full sharing of both the exhaust and compressed air flow paths within the recuperators.
The disclosed multiple turbine system and method with a single, common recuperator is directed to overcoming one or more of the problems outlined above with respect to existing technology.